Conventionally, image processing apparatuses such as electric cameras and the like, which use memory cards having solid-state memory elements as storage media, can store still and moving pictures, and can play back image data stored in the storage media are commercially available. Also, an electric camera which comprises an electric view finder such as a color liquid crystal panel and the like is commercially available.
In these electric cameras, a flash is built in or an independent flash can be mounted as auxiliary light for image capturing in a dark place and environment, so that clear digital photos can be captured even in a dark place such as at night or the like.
A flash device of an electric camera disclosed in Japanese Patent Laid-Open No. 2001-091989 performs pre-emission before main image capturing upon release, calculates the difference between the brightness level and appropriate light control level of an object from a pre-captured image, and determines an emission amount according to the difference upon actual image capturing.
The light control range in this case is generally set to have a focusing area as the center.
FIG. 10 depicts a view for explaining the relationship between a focusing area 912 and light control area 911 on an image capturing frame.
In FIG. 10, since the focusing area 912 and an object 910 overlap each other, a sharp image can be captured even when light control is made based on the light control area 911 having the focusing area 912 as the center. However, in order to capture an image which is in-focus on an object located at the end of the frame, as shown in FIG. 12, after the object 910 is focused, the image capturing range of the camera is moved to capture an image, as shown in FIG. 11. In this case, the object 910 does not match the light control area 910. If light control is made in such state, since the light control is done in an area 920 that does not include any object 910, an image that cannot attain appropriate exposure on the object 910 may be captured.
To solve such problem, Japanese Patent Laid-Open Nos. 2003-107555 and 2003-107567 have proposed a technique for detecting a face of the object 910 from a captured image before AF, and making exposure control or light control by weighting the detected face area of the object. With this arrangement, the face of the object can always be focused without changing any composition after an in-focus state is attained.
However, for example, in a situation with an insufficient brightness (e.g., an image of a person is to be captured to have a nightscape as a background), it is difficult to precisely detect the face of a person from a captured image. As a face detection method of a person, a method of detecting a flesh color area having a predetermined size or larger as a face area, and a method of recognizing a face area by detecting the contour of the face and eye shapes on the basis of brightness information are available. However, with either method, the detection precision undeniably lowers in the dark.